Although a conventional rubber-soled tabi is footwear having work performance and freedom of movement, it is not fit for general sports and ordinarily going out because the toe thereof is split. Furthermore, although some shoes have insteps with a large circumference and some shoes have soft material to prevent hallux vulgas, none of them have any effect on a person whose large toe has been already deformed. On the other hand, although some shoes having partition members inserted into crotch parts are disclosed in some laid-open patent applications, they are unsuitable for many hours of wear because the mere partition member can not deal with the degree of deformation of the big toe. Furthermore, although there are some shoes having sandal straps, they similarly can not effectively and positively prevent the deformation of the big toe. When the big toe bends outside once, it is difficult to correct the hallux vulgas, and therefore, suitable manufactured goods have not been provided yet. Furthermore, there is a safety shoe having a box toe fitted around the toe as a protection member. In this case, although an opening space is formed between the toes, the toes move laterally during walking, thereby increasing fatigue and decreasing work ability.
Known shoe structures are disclosed in: Patent Document 1—Japanese Patent No. 3484118 official gazette; Patent Document 2—Japanese Patent Provisional Publication No. 1997-47302 official gazette; Patent Document 3—Japanese Patent Provisional Publication No. 1997-206101 official gazette; Patent Document 4—Japanese Patent Provisional Publication No. 1997-238701 official gazette; Patent Document 5—Japanese Patent Provisional Publication No. 1999-32805 official gazette; and Patent Document 6—Japanese Patent Provisional Publication No. 2001-128701 official gazette.